1. Field of the Invention
This invention relates to a precision testing instrument capable of performing multiple tests, and more specifically, a precision testing instrument capable of performing fluid measurements.
2. Description of the Prior Art
Various fluid delivery systems, specifically fluid delivery systems designed to administer precise amounts of fluid and/or medication to individuals, require constant calibrations and accuracy tests to ensure safety and functionality. Particularly, intravenous (IV) infusion devices, also known as IV pumps, require calibration at set time periods to verify that the device is functioning properly.
More specifically, medical infusion pumps are designed to deliver over time preset volumes of medicine or intravenous fluids to patients. In most cases, the flow can be preset anywhere from about 1 milliliter per hour to about 1000 milliliters per hour. It is extremely important to check the performance, such as flow rate, delivered volume and occlusion pressure, of these infusion pumps. Although several calibration instruments are currently available, many of them are inaccurate and time consuming to use to make measurements at such low flow rates.
As mentioned above, various tests are performed on these devices, in particular, pressure tests, volume delivery tests, and flow rate evaluation. Conventionally, these tests are performed by trained technicians. This often requires the device to be taken out of service and either shipped to a testing site or moved to a laboratory. The testing process can incorporate various devices including computers and inline flow meters. Conventional methods of performing these tests include using differential pressure readings or occlusion sensing. Both of these methods are time consuming as it is difficult to get an accurate calibration based upon the small rates and the testing devices' design. For example, the Infutest 2000™ manufactured by Datrend Systems Inc. (Canada) injects a bubble into the flow of fluid and tracks the movement of the bubble. The IDA4 Plus Multi-Channel Infusion Device manufactured by Fluke Corporation is a differential pressure flow meter. Both of these devices are relatively slow and require relatively large volumes of fluid for flow measurement.